Torque indicating tool

ABSTRACT

An elongate tool adapted to transmit torsional force applied to one of its ends to a piece of work engaged with its other end and to selectively indicate the foot pounds of force transmitted or to indicate when a pre-set, predetermined foot pounds of force is being transmitted. Said tool comprising a torsion rod with work force receiving and delivery means at its opposite ends and a work force indicating means responsive to torsional deflection of the rod and comprising a primary dial with a primary scale related to one end of the rod and a secondary dial with a vernier scale related to the other end of the rod and to the primary dial, one of said dials being manually adjustable relative to its related end of the rod and the other dial.

United States Patent Grabovac [54] TORQUE INDICATING TOOL [72] Inventor:Bosko Grabovac, PO. Box 1685,

Altadena, Calif. 91001 [22] Filed: Aug. 25, 1970 [21] Appl. No.: 66,838

[52] US. Cl. ..73/139 [51] Int. Cl. ..G0115/24 [58] Field of Search..73/139, 136 A, 1 C, 99; 81/524 R, 52.5; 116/115 [56] References CitedUNITED STATES PATENTS 2,461,491 2/1949 Booth ..73/139 2,607,219 8/1952Millard et a1. ..73/139 2,666,324 1/1954 Stott ..73/99 2,961,771 11/1960Fronek ..116/115 X 3,142,995 8/1964 Forrest ..116/115 X FOREIGN PATENTSOR APPLICATIONS 629,132 9/1949 Great Britain ..73/1 39 PrimaryExaminer-Charles A. Ruehl Attorney-Georges A. Maxwell [57] ABSTRACT Anelongate tool adapted to transmit torsional force applied to one of itsends to a piece of work engaged with its other end and to selectivelyindicate the foot pounds of force transmitted or to indicate when apreset, predetermined foot pounds of force is being transmitted. Saidtool comprising a torsion rod with work force receiving and deliverymeans at its opposite ends and a work force indicating means responsiveto torsional deflection of the rod and comprising a primary dial with aprimary scale related to one end of the rod and a secondary dial with avemier scale related to the other end of the rod and to the primarydial, one of said dials being manually adjustable relative to itsrelated end of the rod and the other dial.

9 Claims, 5 Drawing Figures PATENTED 19 I972 3.691. 826

In (/enfor B a/9o Grabo (/ac;

Hirer/96g TORQUE INDICATING TOOL This invention has to do with animproved torque indicating tool and is more particularly concerned withan elongate torque transmitting structure with work force indicatingmeans to indicate the magnitude of torsioned forces transmitted.

In the hand tool industry, there is a special group, type or class oftool commonly referred to as torque tools, which class of toolsdistinguishes from regular or conventional tools by the addition and/orincorporation of means to indicate or to limit the forces exertedthrough or by the tools. I

Within the above noted class of torque tools, there is provided a numberof special elongate tools wherein torsional forces are applied to oneend thereof, are transmitted therethrough and are conducted thereby ontoor into related work, tool parts or accessories at their other ends.Such tools resemble such standard tools and tool accessories as socketwrench inserts or extensions, screw drivers and the like and would be orare properly defined as torque extensions and torque screw drivers inthe art.

Torque extensions and torque screw drivers are but two examples of whatmight well be described as torque-in, torque-out type tools and arespecifically mentioned as it is this type of torque tool with which theinstant invention is primarily concerned. More specifically, the instantinvention is concerned with that sub-class of torque-in, torque-out typetorque tools, such as socket wrench torque extensions and torque screwdrivers, which operate to indicate the torsional forces transmitted, asdistinguished from that sub-class of such tools which operate to limitthe torsional forces applied.

The torque-in, torque-out force indicating class of torque tool providedby the prior art characteristically includes an elongate torque rod,such as the shank of a screw driver, work force receiving means atoneend of the torque rod, such as the handle of a screw driver, workforce delivery means at the other end of the torque rod, such as thework engaging head of a screw driver, and, torque indicating meansrelated to the rod and/or the work force receiving and delivery means toindicate the torsional forces applied to, conducted through and/ordelivered by the structures.

The simplest and most common form of torque indicating means found insuch structures consists of a dial arranged in fixed position with oneend of the rod and a pointer fixedly related to the other end of the rodand related to the dial, and an appropriate scale on the dial toindicate and show the extent to which the rod is torsionally deflectedwhen the tool is in use. For such a structure to be effective andpractical, the rod must be capable of being torsionally deflected aconsiderable or great extent so that sufficient movement of the pointerrelative to the dial and scale can be effected to make accurate readingof such means possible. For example, such rods must be capable of beingtorsionally deflected as much as 90. To effect 90, or any substantialtorsional deflection of a torque rod in a tool such as referred toabove, the rod must be exceedingly long or must be an exceedingly lightand delicate part, of small cross-sectional extent relative to itslongitudinal extent,

either of which characteristics renders it unsuitable for theestablishment of a small, compact, durable and effective torque tool.

, The above noted characteristic of torque tools of the class hereconcerned with and of the torsion rods employed therein has effectivelyprevented the provision of truly practical, effective and dependabletorque-in, torque-out type tools.

Throughout the years, many attempts have been made by the prior art toovercome the above noted difficulties or shortcomings. Such attemptshave been characterized by the fabrication of torque transmittingassemblies made up of a plurality of leafsprings or the like, whichassemblies are capable of great or considerable torsional deflectionrelative to their longitudinal extent, provide substantial stability andcan be substituted for a simple torsion'rod or tube. While such attemptshave met with some and limited success, they have proven to be much toocostly, fragile and undependable. That success which they haveexperienced can only be attributed to a long and existing demand and/ornecessity for any tool which will serve the end sought to be attained.

Another typical attempt to overcome the above noted difficulties andshortcomings found to exist in torque tools of the class referred to hasbeen to greatly enlarge the scale of the indicating means, to materiallyincrease the swing or sweep of the pointer of said means so as toamplify or magnify the extent of torsion deflection of the torsion rodand to provide a torsion rod which is, in effect, a compromise in lengthand rigidity from that which is truly desirable and from that whichwould otherwise be effective. For such attempts to be effective, thedials have had to be made so large and cumbersome that the resultingstructures have been practically unacceptable. Further, the employmentof a torsion rod, which is a compromise in length and rigidity from thatwhich is desirable and that which would otherwise be required, hasresulted in structures which are larger than practicality demands andwhich are of questionable stability and durability.

An object of my invention is to provide a novel and improved torquetransmitting and indicating means and structure which is particularlyadaptable and serviceable in the establishment of torque tools of thecharacter referred to above.

An object and feature of this invention is to provide a torque toolhaving an elongate torsion rod, work force receiving means at one end ofthe rod, work force delivery means at the other end of the rod andtorque indicating means comprising a primary dial in fixed positionrelative to one end of the rod, and having a primary scale thereon andan auxiliary or secondary dial carried by the other end of the rod endhaving a vemier scale thereon and cooperatively related with the primarydial and scale.

It is an object and feature of the instant invention to provide astructure of the character referred to above wherein the torqueindicating means can effectively and accurately indicate minutes andsmaller fractions of degrees of torsional deflection of the rod andtranslate such deflection into the foot pounds of force required toeffect such deflection whereby the rod can be a short, stout, durableand relatively rigid part.

It is an object and feature of my invention to provide a structure ofthe character referred to wherein the size and extent of the dials whichcarry the scales can be maintained exceedingly small without major ormaterial sacrifice of accuracy and service ability.

fAn object and feature of my invention is to provide a structure of thecharacter referred to wherein one of the-dials is manually adjustablerelative to its related endof the rod andto the other dial whereby theindicating means can be adjusted so that the dials indicate the forceapplied through the-rod when the tool in use or whereby the indicatingmeans can be adjusted and pre-set to predetermined forces-to be appliedand so that the dials can be more readily andconveniently read when thetool; is employed and said predetermined forces are exerted thereby.

In torque tools of the class here concerned with, and provided inaccordance with the teachings of the prior art, the range of force forwhich such tools are designed is determined and controlled by thephysical characteristics of the torsion rod. Accordingly, such toolsdesigned for use in different ranges of force must use speciallyengineered torque rods and must be specially made. i

An object'and feature of my invention is to provide a tool structure ofthe character referred to wherein a single toolstructure can be adaptedfor use in a wide range of force ranges by simply providing one-or bothof the dials with different and appropriate calibrations or scales. g r

it is an object and feature of this invention to provide torqueindicating tool. structures of "the character referred to which are suchthat they can be made small, neat, compact'and well within the range ofsizepermitted for conventional non-torque indicating tools of the sameor similar basic type, such as socket wrench extensions and screwdriverswhereby the tools provided can be advantageously and convenientlyemployed in substantially all mechanical environments where goodmechanical design practices have been followed with respect to theplacement and arrangement of parts and elements to which externaltorsional forces are to be applied 'by means of hand tools.

An object of myinvention istolprovide a structure of thecharacterreferred to which is extremely easy and economicaltomassproduce and which is such that it can be advantageously marketed andsold for a fraction of the cost of tools suitable for like'purposes andof comparable accuracy which areprovided by the prior art.

The above and other objects and features of my invention will beapparentand will be fully understood from the following detaileddescription of typical forms and embodiments of the invention in whichdescription reference is made to the accompanying drawings, in

which: i v

FIG. 1 is an isometric view of a extension embodying my invention;

FIG. 2 is a longitudinal sectional view of the structure shown in FIG.1;

FIG. 3 isan elevational top view of the structure shown in FIG. I;

FIG. 4 is an isometric view of a screw driver embodying the presentinvention; and,

FIG. 5 is a longitudinal sectional view of the structure shown in FlG.4.t The instantinvention embodies a rather simple basic combination andrelationship of parts which can be adapted, arranged and/or embodied ina wide variety of tools, tool parts and devices. In FIGS. 1, 2, and 3 ofthe drawings, the invention is shown related to, or is in the form of, asocket wrench extension, while in FIGS. 4 and 5 of the drawings, it isshown related to, or in the form of, a screw driver.

The basic combination and relationship of parts referred to above andwhich embodies this invention includes an elongate, resilient torsionrod T with work force receiving means R and work force delivery means Pat its opposite ends to receive and to deliver torsional forcestransmittedinto, through, and by the rod T and force indicating means Icarried byand operatively related to the opposite ends of the rod toindicate the torsional forces transmitted by and through the rod. Themeans 1 includes an annular or semi-annular primary dial B with aprimary scale S in radial'spaced relationship about the axis of the rod,support means N securing the dial B in fixed relationship with one endof the rod, an annular or semi-annular secondary auxiliary dial D with avemier scale V in radial spacedrelationship about the axis of the rodand mounting means M supporting the dial D for selective rotationrelative to the other end of the rod, in juxtaposition with the primarydial and with the primary and vemier scales S and V in cooperativerelationship with each other.

In the first, socket wrench extension, form of my invention, shown inFIGS. 1, 2 and 3 of the drawings, the torsion rod 'T is a simple,elongate, vertical stem or shank of predetermined longitudinal andcross-sectional extent and having a predetermined modulus of elasticity.

The upper end of the rod carries the work force receiving means'R, whichmeans 'is shown as an enlarged female box formed integrally on the rodand having a cylindrical exterior 10 and an axially upwardly openingpolygonal socket 11 to cooperatively receive a polygonal drive pin (notshown) on a wrench lever arm or the like. Such a wrench lever arm isshown inphantom lines at A in FIG. 1 of the drawings.

The lower end of the rod carries the work force delivery means P, whichmeans is shown as an enlarged, elongate, axially extending drive pin,polygonal in cross-section and adapted to be cooperatively engaged inthe drive opening of a wrench socket, as illustrated at W in FIG. 1 ofthedr'awings.

The structure thus far described is a typical or conventional socketwrench extension and in practice a standard extension can be utilized inestablishing the foregoing parts and means of the instant invention.

In the form of the invention shown in FIGS, 4 and 5 of the drawings, therod '1" is established by the elongate, vertical shank of a conventionalscrew driver structure. The work force receiving means R is defined bythe enlarged handle of the screw driver construction fixed to the upperendof the-shank or rod T. The work force delivery means D is defined bythe Hattened, narrow, straight-edged, screw driving head formed on thelower end of the rod T'.

The force indicating means I in the first form of the invention includesa flat, horizontally disposed, round, disc-shaped plate 12 with t acentral opening 13 and defining an axially upwardly disposed primarydial or dial face B. The outer peripheral position X of dial B isprovided with two primary scales S, each extending about oppositesegments of the dial face B.

is shifted axially upwardly about the drive pin P and rod T and has itslower end fixed to the drive pin P against relative axial and rotaryshifting and/or displacement.-

ln the case illustrated, the tube of the means N is fixed to the drivepin P by a retaining or keeper pin 16 carried by the tube and engaged inan opening 17 established in the drive pin P.

The'lower terminal end 18 ofthe tube 15 is spaced at sufficient distanceabove the lower end of the drive pin P so that a sufficient portion ofthe pin is exposed and accessible to effect engaging said pin withwrench sockets and the like, in accordance with practice and normal useof wrench extensions.

The upper end ofthe tube 15 terminates'clear of and immediately belowthe lower end of the female drive box of the work force receiving meansR and the dial plate 12 projects radially outwardly from the tube 15, inclose proximity to the means'R.

The secondary dial D of the means lis established by I a flat,horizontally disposed, round, disc-shaped plate 20. The plate 20 issmaller in diametric extent than the plate 12 and has a lower surface 21which opposes and overlies the inner annular portion of the plate 15,leaving the above noted outer portion X of the plate '15 and the scalesS thereon, unobstructed. The plate 20 occurs in close, clear runningrelationship and in axial alignment with the plate 12. t

The outer peripheral portion of the plate 20, defining the dial D, ispreferably beveled and inclined radially outwardly and downwardly asindicated at Z and is pro vided with two vernier scales V, eachextending less than 180 about opposite segmental portions of the dial D.The calibration lines of the scales V extend to the outer peripheraledge 'of the dial D and said outer edge of the dial occurs about theline on the dial B on which the inner ends of the calibration lines ofthe scales S terminate.

Tapering of the dial D, as shown at Z, reduces parallax error betweenthe related scales, when the indicating means is read.

The mounting means M provided to mount the dial D for rotation relativeto the dial B and the rod T is shown as including a flat, annular,upwardly disposed stop shoulder 22 on and about the exterior 10 of thebox of the means R. The shoulder 22 is shown established by a ring 22afixed to the box as by welding w.

The means M next includes an upwardly projecting, downwardly openingcentral cup formed in the plate 20. The cup is greater in insidediameter than the ring 220 and has a flat radially extending top wall 24with a central opening 25. The opening 25 freely receives the box of themeans R and the wall 24 establishes flat, frictional bearing andsupporting engagement on the shoulder 22.

The means M next includes a snap ring groove 26 about the exterior 10 ofthe box in spaced relationship above the wall 24, a snap ring 27 engagedin and projecting radially outward from the groove and an annular,-axially resilient, marcel-type ring 28, or the equivalent thereof,between theouter portion of the snap ring.27 and the wall 24 andnormally yieldingly urging the wall 24 downwardly into pressurefrictional engagement with the shoulder 22 and holding the dial D inpredetermined axial spaced relationship with the dial B.

In practice, if necessary or desired, a back-up washer 29 can be engagedbetween the rings 27 and 28.

The exterior of the cup is preferably scored or grooved and provides afinger engaging knob-like part to facilitate manual rotation of the dialD relative to the dial'B.

With the structure described, it will be apparent that the dial B isfixed relative to the lower end of the rod T, the dial D is selectively,manually rotatable relative to the upper end of the rod T and that thedial D and B are related one to the other so that the scales S and Vthereon are arranged and disposed for cooperative reading andadjustment.

The indicating means I in the second form of the invention is similar tothe means I just described, with minor alteration and re-arranging ofcertain of the parts and/or portions thereof. I

In the second form of the invention, the stop shoulder 22 of the means Mis disposed downwardly and is defined by the lower end of the means R,which is inthe form of an enlarged screw driver handle. The wall 24 ofthe cup 23' is held in frictional engagement with the shoulder 22' bymeans of a marcel washer or ring 28 below the wall 24'. A back-up washer29' is arranged below the rings 28 and a snap ring 27' is engaged belowthe washer 29'. The ring 27' is engaged in a groove 26established in therod T, at its upper end.

The dial D' is an annular radially outwardly disposed dial establishedby the lower end portion or an extension of the cup 23 The lower portionof D is beveled or tapered radially inwardly and downwardly as at Z andis provided with two circumferentially extending vernier scales V aboutits opposite sides and extending less than The means I next includes anelongate, tubular, primary dial B, the outside diameter of which is lessthan the inside diameter of the bell 23 and/or auxiliary dial D'QThedial B has an upper portion occuring within the cup 23 for free relativerotation therein and an outer, lower portion X projecting downwardlyfrom the cup or dial D and on which the primary scales S areestablished. The scales S extend 180 about opposite sides of the dial B.

The dial B is carried by support means N which means includes anelongate carrier tube 15' freely engaged about and extendinglongitudinally of the rod T. The lower end 18' of the tube 15' is fixedto the lower end of the rod T by a pin 16 carried by the tube andengaged in an opening 17 in the rod.

The tube 15' is smaller in diameter than tubular dial B and can be fixedwith the dial in any suitable manner. In the case illustrated, the dialB and tube 15 are formed integrally'with each other, the dial being inthe nature of an enlarged bell-like extension on the upper end of thetube 15'.

. 7 It will be noted'that the first and second forms of the inventionare essentially alike. The major distinctions between the two'notedforms of the invention reside in the fact that the dials in the firstform of the invention are large in diameter and are disposed axiallywhile the dials in the second form of the invention are disposedradially and are relatively small in'diameter. In practice, the radiallydisposed dial means in the second form of the invention and the axiallydisposed dial means inthe first form of the invention could besubstituted one for the other in the respective forms of the inventionwithout departing from the spirit of this invention. I,

. The distinctions between the means R and 'P and the means R and P ofthe first and second forms of the invention clearly illustrate andmakeapparent the fact that the form of suchfmeans is subje'ctto widevariation, without departing fror'n the spirit of the invention.

Thevernier scales V and V and the primary scales S and S' in each formof the invention are cooperatively related so that when thetools are inuse and the rods T and T are subjected to torsional deflection, betweentheir ends, slight deflection is readily detectable by observation orreading of the scales. I

Unlike tools of a similar nature provided by the prior art, wherein theindicating means shows total torsional deflection of the rods directlyon the dials and where torquing the rods to as much as 180 is requiredto ef feet a full range of operation, in both clockwise andcounter-clockwise directions, the provision and use of the auxiliarydials with vernier scales V and V' makes possiblethe effective readingand accurate determination of forces applied on'and through the rods Dand D when they are torsionally deflected to a small or minor extent,for example, 3 or 6, or in more extreme cases, to as much as 10? or l 5.I v y j The abovemakes possible the establishment of tools withrelatively short torsion rods and .of relatively limitedoveralllongitudinal extent, without sacrificing strength, rigidity anddurability.

The above also makes possible the provision of tools capable and adaptedto indicate widely different ranges of force by the provisionof dialswith differing primary and/or secondary or vernierscales, withoutotherwise varying or modifying thebasic tool structure in any manner.

The two, left and right, primary scales S and S of my inventionpreferably extend a full 180", both commencing at a common zero point ormark at one side of their common dial and extending counter-clockwiseand clockwise abouttheir respective halves of the dial, to the other oropposite side of said dial. In the case illustrated in FIG. 3 of thedrawings, the primary scales S extend 180 from to 20. Each scale S isdivided into primary calibrations, O, 5, l0, l5 and 20. The spacesbetween the primary calibrations are divided in 5 segments and provides4 secondary calibrations.

The primary calibrations 0,5, l0, l5, and can, for example, indicate 0to 20, or 0 to 200 foot pounds of force.

The two, left and'right'auxiliary or vernier scales V or V' of myinvention extend less than 180 and are less in circumferential extentthan their related primary scales by a predetermined extent.

The vernier scales V and V preferably start or commence at a common 0point or mark at one side of their related secondary dial and extendcounterclockwise and clockwise toward, butterminate short of the otheror opposite side of said dial. The vernier scales are divided andcalibrated similar to the primary scales, for example and as illustratedin FIG. 3,1they are divided in primary fifths, 0, 5, l0, l5, and 20 andthe spaces between the primary calibrations aredivided into fifths by 4,intermediate, secondary calibrations.

The relative circumferential extent of the related primary and secondaryscales that I provide is subject to considerable and-wide variationandis determined by the physical characteristicsvof the torque rods andthe range of forces that is to be determined and read, or indicated.

In practice and with the structure provided, the force indicating means]or I can be used and read in two distinct manners.

- The first manner is to read forces directly, that is, to read theamount of force exerted onto a piece of. work by means of the toolwithout reference to some pre -set amount of force. I

To effect direct reading, the secondary or auxiliary dial is rotated sothat the zero calibrations of both the primary-and verier scales arealigned. When the zero calibrationsare thus aligned, torqueis applied toa piece of work, throughthe torque rod. If a desired amount is to-beapplied, such is determined when the appropriate calibrations on theappropriate vernier scale is aligned with the corresponding calibratingon the related primary scale. For example, and referring to FIG. 3 ofthe drawings, when No. 15 calibration of the appropriate vernier scaleis aligned with the No.15 calibration on the related primary scale, theforce applied is, for example, foot pounds.

In FIG. 3 of the drawings, the calibrations No. 15 at the upper righthandquarter of the dials arein register. If such register of thescaleswas effected by torquing the structure from a set position wherethe zero calibrations were in normal register, it wouldindicatethatthework was torqued in a counter clockwise direction and 150 foot pounds offorce was applied theretoQThe torque rod in the example given deflectedto the extend noted by the arrows at-the lower side of the noted 7figure of the drawings.

It will be noted that with the dials set in the above manner, a piece ofwork can be torqued as desired and the dials can be read and note madeof the extent to which the work was torqued, in foot pounds of force, orany other suitable and desired measure.

The second manner in which the indicating means can be employed is topre-set the dials to the force which is to be applied to apiece of work.This is effected by manually rotating the auxiliary dial to shift anappropriate, vernier scale so that the calibration thereof indicatingthe force to be applied to the work registers with the correspondingcalibration on the related primary scale. For example,'and as shown inFIG. 3, if a clockwise force of 150 foot pounds to be applied to thework, the right hand scales are adjusted so that IS and 15 are in normalregister. The zero marks are therefore normally out of register'apredetermined extent. Uponapplying force onto the work, it isdeterminable that 150 foot pounds of force is applied when the tworelated zero calibrations are brought into register with each other.

It is to be noted that the right hand scales in FIG. 3 of the drawingsare employed when direct reading of counter-clockwise forces are to beobtained and when the structure is pre-set to indicate clockwise forcesand that the left hand scales are employed when direct reading ofclockwise forces are to be obtained and when the structure is pre-set toindicate counterclockwise forces. To assist the operator of the tool indetermining which scale would be read in each of the noted uses of theindicating means, appropriate arrows can be related to each set ofscales to indicate when that set of scales is to be read, for direct orpre-set readings and to indicate the direction in which torque is to beapplied. The noted arrows, as shown in FIG. 3 of the drawings, can bedesignated by the letters -D- and S- to indicate that they point to thedirection of applied force for direct and pre-set readings on the scaleswith which they are related.

Having described only typical preferred forms and applications of myinvention, I do not wish to be limited or restricted to the specificdetails herein set forth, but wish to reserve to myself anymodifications and/or variations that may appear to those skilled in theart.

Having described my invention, I claim:

1. An elongate torque tool comprising an elongate unitary torsion rodhaving a work force receiving end and a work force delivery end and workforce indicating means comprising a primary dial with a primary scale,the calibrations of which extend circumferentially about the axis of therod in radial spaced relationship thereabout support means between theprimary dial and one end of the rod, a secondary dial with a Vernierscale cooperatively related to the primary dial and scale and mountingmeans between the secondary dial and the other end of the rod, saidVernier scale is shiftable relative to the primary scale upon torsionaldeflection of the rod between its ends and indicates deflection of therod corresponding to a fraction of the distance between the calibrationlines of said primary scale and indicates the foot pounds of forceapplied to effect such deflection of the rod.

shiftable circumferentially relative to said one dial and scale wherebysaid dials can be manually set to foot pounds of force to be applied andsaid force is applied when said dials zero out.

3. A structure as set forth in claim 2 wherein said dials are flat,radially extending concentric discs of different outside diametricextent and define axially disposed faces on which the scales areestablished.

4. A structure as set forth in claim 2 wherein said dials are concentricfreely telescopically engaged cylindrical parts defining axially spacedradially outwardly disposed surfaces on which the scales areestablished.

5. A structure as set forth in claim 2 wherein the primary and secondarydials are provided with two primary and two Vernier scales extendingabout the dials in opposite directions to selectively indicate clockwiseand counter-clockwise torsional deflection of the rod.

6. A structure as set forth in claim 2 wherein the work force receivingend of the rod has a female box with an axially outwardly openingpolygonal pm receiving socket and said work force delivery end of therod has an axially extending elongate polygonal drive pin.

7. A structure as set forth in claim 2 wherein the work force receivingend of the rod has an enlarged, elongate, axially extending handle andsaid work force delivery end of the rod has a work engaging head.

8. A structure as set forth in claim 2 wherein the support meansincludes an elongate support tube surrounding and extendinglongitudinally of the rod, a keeper pin securing one end of the tube tosaid one end of the rod and means securing the primary dial to the otherend of the tube, said mounting means including an axially disposedannular shoulder on the rod adjacent said other end of the rod, aradially disposed wall on thesecondary dial and retaining meansyieldingly urging the said wall into frictional bearing engagement onsaid shoulder.

9. A structure as set forth in claim 8 wherein the work force receivingend of the rod has an enlarged, elongate axially extending handle andsaid work force delivery end of the rod has a work engaging head, saidretaining means including a groove in the rod spaced axially from theshoulder, a snap ring engaged in the groove and an axially resilientspring ring engaged between the snap ring and the wall and urging thewall toward the shoulder.

1. An elongate torque tool comprising an elongate unitary torsion rodhaving a work force receiving end and a work force delivery end and workforce indicating means comprising a primary dial with a primary scale,the calibrations of which extend circumferentially about the axis of therod in radial spaced relationship thereabout support means between theprimary dial and one end of the rod, a secondary dial with a Vernierscale cooperatively related to the primary dial and scale and mountingmeans between the secondary dial and the other end of the rod, saidVernier scale is shiftable relative to the primary scale upon torsionaldeflection of the rod between its ends and indicates deflection of therod corresponding to a fraction of the distance between the calibrationlines of said primary scale and indicates the foot pounds of forceapplied to effect such deflection of the rod.
 2. A structure as setforth in claim 1 wherein one of said dials and scales is in fixedposition relative to its related end of the rod and the other dial andscale is shiftable circumferentially relative to said one dial and scalewhereby said dials can be manually set to foot pounds of force to beapplied and said force is applied when said dials zero out.
 3. Astructure as set forth in claim 2 wherein said dials are flat, radiallyextending concentric discs of different outside diametric extent anddefine axially disposed faces on which the scales are established.
 4. Astructure as set forth in claim 2 wherein said dials are concentricfreely telescopically engaged cylindrical parts defining axially spacedradially outwardly disposed surfaces on which the scales areestablished.
 5. A structure as set forth in claim 2 wherein the primaryand secondary dials are provided with two primary and two Vernier scalesextending about the dials in opposite directions to selectively indicateclockwise and counter-clockwise torsional deflection of the rod.
 6. Astructure as set forth in claim 2 wherein the work force receiving endof the rod has a female box with an axially outwardly opening polygonalpin receiving socket and said work force delivery end of the rod has anaxially extending elongate polygonal drive pin.
 7. A structure as setforth in claim 2 wherein the work force receiving end of the rod has anenlarged, elongate, axially extending handle and said work forcedelivery end of the rod has a work engaging head.
 8. A structure as setforth in claim 2 wherein the support means includes an elongate supporttube surrounding and extending longitudinally of the rod, a keeper pinsecuring one end of the tube to said one end of the rod and meanssecuring the primary dial to the other end of the tube, said mountingmeans including an axially disposed annular shoulder on the rod adjacentsaid other end of the rod, a radially disposed wall on the secondarydial and retaining means yieldingly urging the said wall into frictionalbearing engagement on said shoulder.
 9. A structure as set forth inclaim 8 wherein the work force receiving end of the rod has an enlarged,elongate axially extending handle and said work force delivery end ofthe rod has a work engaging head, said retaining means including agroove in the rod spaced axially from the shoulder, a snap ring engagedin the groove and an axially resilient spring ring engaged between thesnap ring and the wall and urging the wall toward the shoulder.